Kerry Green was a "blue baby," born in 1964 in Tulsa, Okla., and his family was given little hope that he would live because of a malformed aorta.
But by 3 years old and several heart surgeries later, Green was being described by doctors as a "miracle child," small for his age at 23 pounds, but a "real live wire."
What doctors didn't know then was that the boy had a more serious underlying condition, a rare blood condition called methemoglobinemia -- the same disorder that affected the Blue Fugates of Kentucky.
"I was picked on as a kid in elementary school because I am blue," said Green, who is now 46. "I look dead. My lips are purple and my fingernails and toes are dark."
Today, Green lives in Seattle and is disabled, but he said he believes finding a genetic connection to the Fugates may help him learn more about the father he never knew.
"I am positive my father had the condition -- they all told me," said Green. "I did see one kind of blurry picture of him and you could almost see it. He's got the pale look I do."
Raised by his grandparents, Green said he doesn't even know if his father is alive. Bob Green, who would be 73, had been a long-haul truck driver with relatives who had migrated west from Tennessee.
A sister was put up for adoption and Green doesn't know the whereabouts of two brothers. His mother wandered in and out of his life.
"I just want to know where I came from and to know that side of my family history," said Green. "It's hard to describe and it's kind of weird not knowing where the condition of mine came from. People have pointed out the Fugates to me before."
Seven generations of the Fugates lived an isolated pocket of Appalachia, passing down a recessive gene that turned their skin blue through in-breeding.
In the 1980s and 1990s, the mountain people dispersed, and the family gene pool became much more diverse. Other relatives, perhaps like Green's paternal relatives, scattered throughout Virginia and Arkansas.
Even today, "you almost never see a patient with it," said Dr. Ayalew Tefferi, a hematologist from Minnesota's Mayo Clinic. "It's a disease that one learns about in medical school and it's infrequent enough to be on every exam in hematology."
In the mildest form, methemoglobinemia causes no harm, and most of the Fugates lived well into their 80s. But in Green's case, his body is starved of oxygen and every organ is affected.
Methemoglobinemia is a blood disorder in which an abnormal amount of methemoglobin -- a form of hemoglobin -- is produced. Methemoglobin cannot effectively release oxygen.
Hemoglobin is responsible for distributing oxygen to the body and without oxygen, the heart, brain and muscles can die.
"I don't breathe very well," said Green. "The red blood cells don't give me enough oxygen."
Green's condition was such an anomaly that hematologists at the Dana Farber Cancer Institute in Boston paid for him to fly East several years ago just to study him.
A former construction worker and welder, Green is married and has two children --- 27 and 15 -- neither of whom has the disorder.
Most of what is known about methemoglobinemia comes from one doctor's study of the Fugate ancestry in the early 1960s. Dr. Madison Cawein III, a hematologist at the University of Kentucky's Lexington Medical Clinic, drew family charts and blood samples to better understand the genetic disorder.
The most detailed account, "Blue People of Troublesome Creek," was published in 1982 by the University of Indiana's Cathy Trost.
The ancestral line began with a French orphan, Martin Fugate, who settled in Eastern Kentucky. Isolation and in-breeding passed on the disorder.
The last in the direct line of Fugates to inherit the gene was Benjamin "Benjy" Stacy, whose skin at birth was "as Blue as Lake Louise," according to doctors at the time. He now lives in Alaska, according to Facebook.